Alarm-lock.



UNTTED STATES PATENT OFFICE.

JAKOB GRABER, OF ZURICH, SWITZERLAND.

ALARM-LOCK.

SPECIFICATION formingpart of Letters Patent No. 715,053, dated December 2, 1902.

Application filed June 7, 1902. $erial No. 110,657. (No model.) 7

To a, whom it may concern:

Be it known that I, JAKOB GRABER, a citizen of Switzerland, residing in Zurich, in the canton of Zurich, Republic of Switzerland, (whose post-office address is No. 454 Badenerstrasse, Zurich,) have invented certain new and useful Improvements in Alarm-Locks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying d rawiugs,

and to numerals of reference marked thereon,

which form a part of this specification.

I have applied for patents in the following countries: Switzerland, on 13th of November, 1901; Austria, on th of November, 1901; Hungary, on 4th of December, 1901; Germany, on 1 1th of April, 1902; France, on 5th of May, 1902; Belgium, on 9th of May, 1902; Italy, on 9th of May, 1902.

The subject of the present invention is an alarm-lock, the object of which is to give an alarm when it is opened by means of a key differing only a very little in the dimensions of its wards from the correct key, but gives no alarm when opened by the correct key.

In the accompanying drawings, Figure 1 is a front view with the front plate of the lock removed, parts being shown in section. Fig. 2 shows a section along the line 00min Fig. 1, and Fig. 3 such a one along the line y y in Fig. 1.

At both sides of the bolt 2, displaceable within the casing 1, there are arranged two bell-crank levers, the two arms of each of whichare marked 4 and 5. Each bell-crank lever is pivoted on a pin 3 and being under the action of springs 22. The arms 4. are curved in an arc struck from the center of the keyhole in the lock, and when the key is insertedthat is to say, at the position shown they rest on the two side edges of the keyward 6, so that at the turning of the key the two bell-crank levers experience no movement. Underneath the bell-crank levers there are two hammers or alarm-controlling parts 8, pivoted on a pin 7, which are each drawn down by a spring 9, attached to the casing, but are, however, prevented in this movement by an arm 10, jointed to the bolt 2. The arm 10 is continually pressed to the left by a spring 11. WVithin the reach of the hammer 8 there is provided a bed 12 for two detonating cartridges 13, which latter can be ignited by striking of the hammers 8. At the other end of each of the hammers 8 there is a contact-spring 1 1, to which a spring 15, arranged insulated on the casing, stands opposite. This springis connected by wiring with the one pole of a source of electricity, while the casing 1 is connected with the other pole of the source of electricity. In the circuit there is intercalated an electrical souuder for eXample,-the house-bell-which is set in activity when the circuit is closed. If one of the hammers 8 sinks forward, then the spring 14 strikes against the spring 15 and closes the circuit, so that the current coming from the source of electricity goes back from the metallic casing by means of the pins 7 to the hammer 8, spring 14, and from here to the spring 15 and through the sounder back to the source of electricity. Each hammer has a projecting pin 16, which in the position denoted is opposite to the arm 5 of the bellcrank lever l 5. The lock has, further, a slide 17, which by a spring 19 on a pin 18 and a two-armed lever 21, engaging a cross-pin 20 of the pin 18, is continually pressed 0utward that is to say, against the closing-cap 24:, fitted on a door-post. The pin 18 lies with its front end against the arm 10.

The mode of action of the alarm-lock is as follows: In the locked condition of the lock and with the key drawn out the arms 4 are by the springs 22 pressed so far downward that the arms 5 strike on the pins 23 and are not opposite to the projections 16, Fig. 1, dotted position. If now the key belonging to the lock be inserted therein and turned in the direction denoted by the arrow, then the two arms 4 are brought into the position denoted by full lines, in which the arms 5 are opposite the projections 16. In consequence of the curvature of the armst the position of the arms 5 is not then altered if the bolt is pushed by the key into its rearmost position, in which position,too,the arm 10 again prevents a turning of the hammers 8. If it be attempted to push back the bolt by means of askeleton or burglars key, whose ward is of diiferent length from that of the true key, then during the turning of the skeleton or burglars key the two arms 4 take up a position different from that shown in full lines, so that the arms 5 no longer stand opposite to the projections 16. If now the attempt to throw back the bolt a slight amount be successful, then the arm 10 of the bolt comes over a recess 81, arranged in the front hammer 8, whereupon the latter is drawn down by the spring 9, the detonating cartridge ignites,and thereby alarms the house. With the turning of the hammer 8 the spring 14 comes into contact with the spring 15, so that the circuit already mentioned is closed and the sounder intercalated therein is actuated. If it be attempted by a second turning of the skeleton or burglars key to bring the bolt into the rearmost position, then the arm 10 com es over a recess 82 of the rear hammer 8, so that this, too, is drawn down by its spring 8, and thereby ignites the detonating cartridge belonging to it. Should a forcible opening of the lock or the door belonging to it be attempted by removal or forcing aside of the closing-cap 24, then after the separation of the two the bolt 17, which is under the influence of the spring 19, springs forward, while the pin 18 is moved backward, and the arm 10, jointed to the bolt and under the pressure of the spring 11 turns to the rear, so that both hammers 8 lose their point'of support and are drawn downward by their springs 9, whereby again the detonating cartridge is ignited and the sounder actuated. g

It is evident that my alarm system is applicable' to locks of all sorts, such as locks proper, bolt-locks, bolts, &c.

What I claim is" 1. In combination,in alock,means for holding a detonating body, a circuit-closer, a hammer controlling both the ignition of the detonating body and the circuit-closer,a bolt having an arm pivoted thereto, said arm controlling the release of the hammer, a bellcrank lever arranged to be operated by the key and controlling the movement of the hammer, a slide normally retracted when the door is closed, a spring for forcing the said slide outwardly when the door is opened or forced and means controlled by the slide for in turn controlling the position of the arm of the bolt, substantially as described.

2. In combination with a sliding bolt, a pivoted part controlling an alarm, a bell-crank lever arranged to be operated by the keywards and in turn controlling the pivoted part, a pivoted arm on the bolt also controlling the pivoted part which controls the alarm and a slide normally retracted when the door is closed, said slide being spring-pressed and controlling the pivoted arm to alter its position in relation to the pivoted part, substantially as described.

3. In combination in a lock, a slide normally pressed back into the lock when the door is closed by contact with the part opposite the face of the look, a spring for forcing the slide outwardly, a bolt, an arm pivoted thereto and controlled by the said slide and an alarm-controlling part controlled by the position of the pivoted arm on the bolt, substantially as described.

In testimony that I claim the foregoing I have hereunto set my hand this 24th day of May, 1902.

JAKOB GRABER. WVitnesses:

A. LIEBERKNEOHT, HERMANN HUBER. 

